Here is some more description from their shopping page (https://shop.nitrokey.com/shop/nitrophone-10-880?category=4)

The NitroPhone 10 combines security, privacy and ease of use with modern hardware. Long-term software updates of up to 7 years guarantee sustainability and a low price per time. The NitroPhone is based on the high-quality Pixel hardware and GrapheneOS , the most hardened Android for private and professional. Gain full control of your smartphone without Google, Apple, and cloud!

btw: I'm not affiliated with them. Just found this on the internet.

These all seem ridiculously overpriced. And then if you do want to get microphone desoldered it costs the price of another phone..... This looks like they are just trying to market towards enterprise that's the only people I know that courd reasonably afford those prices.